The present invention concerns reaction of alkenes, including cycloalkenes. In this specification, references to alkenes should be construed as covering alkenes and cycloalkenes where appropriate.
In one aspect the present invention provides the Lewis acid-catalysed reaction of an alkene with an epoxide. This is a novel reaction, useful for synthesis of various fragrance materials (known and novel) and their intermediates.
One of the main products of reaction is an alkanal (or aldehyde), and the reaction of the invention appears to be generally applicable to the synthesis of homologous aldehyde from open-chain alkenes. The resulting aldehyde may then be subjected to further reaction, such as reduction to the corresponding alkanol (or alcohol).
In a further aspect, the present invention thus provides a method of synthesis of an aldehyde by Lewis acid-catalysed reaction of an alkene with an epoxide.
For example, reaction of cyclododecene and propylene oxide produces 2-(cyclododecyl) propan-1-al. This alkanal can be readily reduced to the corresponding alkanol, 2-(cyclododecyl)propan-1-ol, e.g. by catalytic reduction using sodium borohydride. 2-(cyclododecyl)propan-1-of is a known compound which exhibits an intense and tenacious odour of amber character, and so is useful in fragrance compositions and in perfumed products, and is normally made from cyclododecanone in a more complex, costly and hazardous synthesis. The present invention thus provides an alternative route to production of the useful fragrance material 2-(cyclododecyl)propan-1-ol.
In a preferred aspect, the invention thus provides a method of producing 2-(cyclododecyl) propan-1-ol, comprising treating cyclododecene with propylene oxide in the presence of a Lewis acid catalyst to produce 2-(cyclododecyl)propan-1-al, and reducing the 2-(cyclododecyl)propan-1-al to 2-(cyclododecyl)propan-1-ol.
A major by-product of the first step of this reaction is 2-methylperhydrocyclododeca[b]furan, which is also a known fragrance compound exhibiting a woody-amber odour, and which is marketed by Wacker under the trade name xe2x80x98Lignoxanxe2x80x99. xe2x80x98Lignoxanxe2x80x99 is also normally made from cyclododecanone by a multistage procedure.
The present invention thus provides a novel route to produce two known useful fragrance materials, 2-(cyclododecyl)propan-1-ol and 2-methylperhydrocyclododeca[b]furan, by Lewis-acid catalysed-reaction of cyclododecene with epoxide.
The use of SnCl4 as the Lewis acid is thought to be beneficial.
As a further example, reaction of 1,5,9-cyclododecatriene and propylene oxide produces 2-(cyclododecadienyl)-1-propanal. This material can be reduced, e.g. with sodium borohydride, to the corresponding alcohol, 2-(cyclododecadienyl)-1-propanol, which is a novel compound which exhibits an odour of amber and is the subject of our co-pending European patent application No. 97308580.6. Catalytic hydrogenation of 2-(cyclododecadienyl)-1-propanol yields 2-(cyclododecyl)propan-1-ol.
A minor product of the reaction of 1,5,9-cyclododecatriene and propylene oxide is 2-methyl-2,3,3a,4,5,8,9,12,13,13a-decahydrocyclododeca[b]furan, which can be hydrogenated to give xe2x80x98Lignoxanxe2x80x99.
Minor components of the reaction of 1,5,9-cyclododecatriene with propylene oxide have been found to exhibit an intense blackcurrant odour that has been attributed to the novel compound 2-methylperhydro-as-indacenol[3a,3-b]furan that is the subject of our co-pending European patent application No. 9730851.4.
The present invention also includes within its scope products (direct and indirect) of reactions in accordance with the invention. Those reaction products having fragrance properties may be used as such to impart, strengthen or improve the odour of a wide variety of products, or they may be used as a component of a perfume to contribute its odour character to the overall odour of such perfume. For the purposes of this invention a perfume is intended to mean a mixture of fragrance materials, if desired mixed with or dissolved in a suitable solvent or mixed with a solid substrate, which is used to impart a desired odour to the skin and/or any product for which an agreeable odour is indispensable or desirable. Examples of such perfumed products are: fabric washing powders, washing liquids, fabric softeners and other fabric care products; detergents and household cleaning, scouring and disinfection products; air fresheners, room sprays and pomanders; soaps, bath and shower gels, shampoos, hair conditioners and other personal cleansing products; cosmetics such as creams, ointments, toilet waters, preshave, aftershave, skin and other lotions, talcum powders, body deodorants and antiperspirants, etc.
Other fragrance materials which can be advantageously combined with the reaction products according to the invention in a perfume are, for example, natural products such as extracts, essential oils, absolutes, resinoids, resins, concretes etc., but also synthetic materials such as hydrocarbons, alcohols, aldehydes, ketones, ethers, acids, esters, acetals, keta""s, nitrites, etc., including saturated and unsaturated compounds, aliphatic, carbocyclic and heterocyclic compounds.
Such fragrance materials are mentioned, for example, in S. Arctander, xe2x80x9cPerfume and Flavor Chemicalsxe2x80x9d (Montclair, N.J., 1969), in S. Arctander, xe2x80x9cPerfume and Flavor Materials of Natural Originxe2x80x9d (Elizabeth, N.J., 1960) and in xe2x80x9cFlavor and Fragrance Materialsxe2x80x941991xe2x80x9d, Allured Publishing Co. Wheaton, Ill. USA.
Examples of fragrance materials which can be used in combination with the reaction products according to the invention are: geraniol, geranyl acetate, linalol, linalyl acetate, tetrahydrolinalol, citronellol, citronellyl acetate, dihydromyrcenol, dihydromyrcenyl acetate, tetrahydromyrcenol, terpineol, terpinyl acetate, nopol nopyl acetate, 2-phenylethanol, 2-phenylethyl acetate, benzyl alcohol, benzyl acetate, benzyl salicylate, styrallyl acetate, benzyl benzoate, amyl salicylate, dimethylbenzyl-carbinol, trichloromethylphenylcarbinyl acetate, p-tert-butylcyclohexyl acetate, isononyl acetate, vetiveryl acetate, vetiverol, xcex1-hexylcinnamaldehyde, 2-methyl-3-(p-tert-butylphenyl)propanal, 2-methyl-3-(p-isopropylphenyl)propanal, 3-(p-tert-butylphenyl)-propanal, 2,4-dimethylcyclohex-3-enyl-carboxaldehyde, tricyclodecenyl acetate, tricyclodecenyl propionate, 4-(4-hydroxy-4-methylpentyl)-3-cyclohexenecarboxaldehyde, 4-(4-methyl-3-pentenyl)-3-cyclohexenecarboxaldehyde, 4-acetoxy-3-pentyl-tetrahydropyran, 3-carboxymethyl-2-pentylcyclopentane, 2-n-heptylcyclopentanone, 3-methyl-2-pentyl-2-cyclopentenone, n-decanal, n-dodecanal, 9-decenol-1, phenoxyethyl isobutyrate, phenylacetaldehyde dimethylacetal, phenylacetaldehyde diethylacetal, geranyl nitrile, citronellyl nitrile, cedryl acetate, 3-isocamphylcyclohexanol, cedryl methyl ether, isolongifolanone, aubepine nitrile, aubepine, heliotropin, coumarin, eugenol, vanillin, diphenyl oxide, hydroxycitronellal, ionones, methylionones, isomethylionones, irones, cis-3-hexenol and esters thereof, indan musks, tetralin musks, isochroman musks, macrocyclic ketones, macrolactone musks, ethylene brassylate.
Solvents which can be used for perfumes which contain products according to the invention are, for example: ethanol, isopropanol, diethyleneglycol monoethyl ether, dipropylene glycol, diethyl phthalate, triethyl citrate, isopropyl myristate, etc.
The quantities in which reaction products according to the invention can be used in perfumes or in products to be perfumed may vary within wide limits and depend, inter alia, on the nature of the product, on the nature and the quantity of the other components of the perfume in which the compound is used and on the olfactive effect desired. It is therefore only possible to specify wide limits, which, however, provide sufficient information for the specialist in the art to be able to use reaction products according to the invention for his specific purpose. In perfumes an amount of 0.01% by weight or more of the reaction product according to the invention has been found to have a clearly perceptible olfactive effect. Preferably the amount is 0.1 to 80% by weight, more preferably at least 1%. The amount of the reaction product according to the invention present in products will frequently be at least 10 ppm by weight, preferably at least 100 ppm, more preferably at least 1000 ppm. However, levels of up to about 20% by weight may be used in particular cases, depending on the reaction product and the product to be perfumed.
The present invention thus also includes within its scope perfumes and perfumed products incorporating products of reactions in accordance with the invention.